DIY Guide rings and the third screw

Having previously made a more stable mounting solution for my guide scope I have since found that I needed to take it to the next level.
A decent set of guide scope rings from what I have seen cost around £80 – £100 and not something I was prepared to pay.
The main reason behind wanting a better solution was so I could align the guide scope with my main scope and enable me to platesolve targets.

I set about doing a bit of research and found a number of different DIY solutions so decided to have a go at making a set myself.

Guide scope and rings completed
Guide scope and rings completed Skywatcher 9×50 guide scope and QHY5L-IIM Camera

A quick search on ebay resulted in my buying a section of Aluminium tube, the best part here was that the company offered a free cuttiing service.
I ended up purchasing a 100mm section with 10mm walls, 70mm outside diameter and requested they cut two 20mm sections for me.
A few days later this arrived as stated and was ready to start working with.

At this stage I employed the help of a good mate who let me borrow a drill press and a few taps.

I marked and drilled three holes for each of the bolts and a fourth to mount the ring to the dovetail bar.
The three bolt holes on each ring then got tapped using an M5 tap and the fourth was a 1/4″ Tap to match the holes on the skywatcher dovetail bar.
One everything was tapped I then gave the rings a quick going over with fine sand paper to get any sharp edges off and cleaned everything with Isopropyl Alcohol.
I used M5 Stainless steel bolts to prevent rusting and hold better than normal nylon bolts found in some of the cheaper guide scope rings that I had looked at.
The rings are then bolted to the dovetail using 1/4″ Hex bolts.

A simple Guided DSLR setup.
A simple Guided DSLR setup.

This should give me ample scope for adjustment and I can honestly say is as solid as a rock. For reference the Scope is a skywatcher 9×50 finder scope with a QHY5L-IIM camera, everything needed for this including the adaptor to mount the camera can be at Modern Astronomy who I highly recommend.

Whilst I was at it I also decided to create a setup that I was able to use without the telescope for guiding a DSLR. Drilled an extra hole towards the rear of the dovetail
Large enough for an M10 Bolt. This has enabled me to mount a Ballhead at the rear of the guide scope and attach a DSLR and lens.
This I am hoping to use for imaging a wider focal lengths than I could with the telescope but still retain the ability to guide.
In total the entire cost of making the guide rings was around £15 including the Alu tube section and bolts. Additional costs would be involved if you wanted to setup the guided DSLR ring but again would not cost the earth and would not total more than £50 depending on the ballhead.

 

One of the other issues that I have faced since day one is camera tilt. As standard the standard focuser although very good only has two screws holding the camera

cof
cof

and coma corrector in place. I have to be very careful when attaching these otherwise I get a small amount of tilt in the imaging train that shows up in the resulting images. I had looked to see about getting a replacement such as a clicklock or something but there seemed to be very little around.

A ended up going down the route of adding a third screw to the standard adaptor instead. The standard bolts are perfectly fine for the job however they are very small a not easy to turn with cold fingers or gloves.
A quick search on ebay and a few days later a set of better M4 bolts arrived with larger knurled tops. These are large enough to be able to grip a lot easier but not so big that they get in the way of anything.
I drilled and tapped a third hole and everthing is complete.

The third screw I can tell streight away has made a massive difference and mating the camera and coma corrector to the focuser tube is now a lot easier and with no tilt at all.

I will post an update in regards to how the guide scope rings perform once I get a chance to get out and test them and all being well will also be able to give a bit of a more in-depth look at platesolving as an alternative to star alignment.

 

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